While the document is beamed outside the security of the corporate firewall, Zoho says it doesn't permanently store user data. When a document is opened in SharePoint, a copy is transferred with 256-bit encryption to Zoho servers for viewing and editing. The data is then completely deleted from the servers when the document closes, according to the company.

Zoho says Microsoft Sharepoint permissions are also respected, so users can't share a document from the Zoho web interface with users who don't have access to the document in Microsoft SharePoint.

The document gets saved in the original format it was created in (.doc, .xls, .ppt, etc) so it can still be fiddled with on more traditional in-house (viz: Microsoft) productivity apps afterwards. Users can also create documents, speadsheets and presentations through the Zoho Office editor.

Basically, the difference here between vanilla Zoho Office and Zoho Office for Microsoft SharePoint is that the former stores files on Zoho's servers, while the latter puts it back behind the corporate firewall after the user is done.

Zoho's SharePoint add-on is available now for Microsoft SharePoint 2007 and 2003. There's a 30-day free trial, and after that, a monthly subscription is $3 per user and a yearly subscription is $24 per user. ®